This invention relates to a method operating of a laser and to a laser apparatus.
There are different kinds of gas laser that employ a heavy noble gas, that is one or both of xenon and krypton, as a component of the lasing gas. In particular, carbon dioxide lasers use a premixed lasing gas, which is a mixture of carbon dioxide, a heavy noble gas, and one or more of helium, nitrogen, oxygen and carbon monoxide. The typical xenon content is between 1 and 3% by volume.
The lasing gas is fed into the lasing chamber of the laser as a continuous steam or intermittently, while the laser is continuously or periodically exhausted, typically by means of a vacuum pump. In this way the lasing chamber is continuously purged so as to ensure optimal operation. The waste gas, including xenon, is released into the atmosphere and therefore lost.
It is known to recover and recycle a noble gas from a gas mixture. Typically, pressure swing adsorption processes are used for this purpose. Examples are given in WO2005/03116 A and WO2006/067384 A. Such methods have drawbacks if used with lasers.